There were no such issues during the beta testing as far as I know at least.
It sounds odd that a shutdown would make the wifi go into som error state that blocks the whole machine from booting, but everything is possible I guess.
As an electronics engineer it sounds equally likely thought that some hardware error on the wifi card just happened to occur when the printer was shut down and that this fault is completely unrelated to what the printer was doing before it was shut down.

Anders Olsson wrote:It can be so frustrating to know all these things, like the filament sensor and why it is not there, but not knowing if one is allowed to talk about it or not.

There is no clear (read official) statement about what we can talk about and what not. But as far as I'm concerned; anything that's inside the machine (or are traces of in uncompiled code) are free to talk about.

Anders Olsson wrote:It can be so frustrating to know all these things, like the filament sensor and why it is not there, but not knowing if one is allowed to talk about it or not.
I am not taking any chances posting information that might be unofficial, that is for sure, so I just have to sit there keeping silent and hope that someone from Ultimaker steps in and explains things.

So thank you for that post nallath, one thing less on my list of things that I am not allowed to talk about

Though you and others know way more than I do(people had an UM3 for testing , I believe I just heard the word core once, a long while ago), I was aware of some tiny things like this filament sensor thing Screaming at myself because I couldn't post about it when I read people complaining/discussing it. But hey, I rather know things I cannot tell than being able to talk nonsense because I don't know anything